Furnace.



PATENTED JAN. 22, 1907.

d 6 v Ill f 1 4 m L. A. DOLLFUS.

FURNACE. APPLIUATION FILED JULY 17. 1905.

LUCIEN ANTOINE DOLLFUS, OF PARIS, FRANCE.

FURNACE.

- Specification of Letters Patent.

Patented Jan. 22, 1907.

Application filed July 17, 1905. Serial No. 270,076.

T0 at whom, it may concern:

Be it known that I, L-UcIEN ANTOINE DOLLFUS, a citizen of the French Republic, and a resident of Paris, France, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

The present invention relates to improvements in furnaces.

Reducing furnaces, smelting furnaces, shaft-furnaces, and all furnaces in which intense heat is to be generated work better when they are operated with heated air.

The object of the present invention is to utilize the heat of the grate-fire, which is otherwise lost by radiation, for heating up the air, whereby the use of all special apparatus is avoided.

One embodiment of the present invention is illustrated merely by way of example in the accompanying drawings, which shows the application of the invention to an ordinary shaft-turnace, such as is used, for example, in annealing.

Figure 1 shows the inner arrangement of the furnace in perspective view. Fig. 2 is a cross-section through the rear wall.

In order that the invention may be more clearly understood, details which do not form part of the invention are not shown in the drawings. For example, the grate-bars, the door, and the closing device are omitted.

The air-admission pipe 0 enters at a through the wall 6 below the grate-bars, (not shown) which are arranged on an offset (1 of the wall, and said pipe in the form of many windings or zigzags runs to nearly the bottom of the lower part of the furnace and ends in box-like chambers e, which are provided with outlet-openings on their two par allel sides f f, which are situated opposite one another, through which openings the air passes into the space under the grate. Fig. 2 shows that a frame is placed on the offset (1 to receive the grate-bars; but the latter may be placed with their ends directly on said offset of the brickwork. It is clear that the air inthe course of the long way along which it must pass from its entrance at a to its exit through the sides f f is heated to a high degree, because the heat radiated from the grate is readily absorbed and retained by the ering the brick walls of the ash-pit under the grate, said pipe formed of a plurality of regular and narrow-spaced returns, the uppermost return formed at its end with a bend passing through the brickwork under and near the grate and communicating with the atmosphere, box-like chambers, 6, provided with outlet-openings, f, toward the ash-pit and arranged in the lower part of said ashpit, the lowermost return of said pipe, 0, being formed at its end with a bend communicating with the said chambers e.

In testimony whereof I have hereunto affixed my signature, this 28th day of June, 1905, in the presence of two witnesses.

LUCIEN ANTOINE DOLLFUS.

Witnesses:

PAUL EMILE BARAST, ALBERT GERBERON. 

